One piece compass formed of plastic material



E. ZACHS Sept. 28, 1965 ONE PIECE COMPASS FORMED OF PLASTIC MATERIAL Filed 001;. 8, 1965 INVENTOR. I

EDWARD ZACHS a United States Patent 3,208,149 ONE PIECE COMPASS FORMED OF PLASTIC MATERIAL Edward Zachs, West Hartford, Conn., assignor to The C-Thru Ruler Company, Hartford, Conn., a corporation of Connecticut Filed Oct. 8, 1963, Ser. No. 314,686 2 Claims. (Cl. 33-157) The present invention relates to a one piece compass formed of plastic material and it consists in the combinations, constructions and arrangements of parts hereinafter to be described.

Generally there is provided a compass adapted to be formed of a plastic material in a single molding operation. The device consists of a pair of legs integrally interconnected by an inverted U-shaped arch atop which is integrally formed a vertically and upwardly extending handle. A curved arm is integrally formed with one of the legs and extends through a slot formed in the other leg. The curved arm is provided with indicia and the lower edge thereof provided with serrations which are adapted to receive an upwardly extending tooth positioned in the lower end of the slot. The slotted leg terminates at its lower end in a point while the other leg is foreshortened and terminates in a cylindrical pencil holder having a longitudinal slot therein. Each of the legs is provided on its inner side with a strengthening web, the webs being so positioned as to overlap when the legs are brought together. The device is made of a plastic material possessing memory, that is to say a material which will spring back or return to its original position after being moved to another position. Hence the pencil holder acts to securely grip a pencil placed therein, the legs tend normally to move apart but are held in selected position by the tooth cooperating with the serrations.

It is accordingly an object of the invention to provide a compass of single piece construction.

Another object of the invention is to provide a device of the character set forth which may be molded in a single operation.

A further object of the invention is to provide a device of the character set forth which is simple in construction, inexpensive to manufacture and yet effective and efiicient in use.

Still another object of the invention is to provide, in a device of the character set forth, novel means for locking the legs thereof in selected positions.

A still further object of the invention is to provide, in a device of the character set forth, novel means for strengthening the legs of the same.

Other and further objects of the invention will become apparent from a reading of the following specification taken in conjunction with the drawing, in which:

FIGURE 1 is a side elevational view of an embodiment of the invention,

FIGURE 2 is a sectional view taken substantially along line 2-2 of FIGURE 1,

FIGURE 3 is a plan View of the device illustrated in FIGURES 1 and 2,

FIGURE 4 is an enlarged sectional view, with certain parts removed, taken substantially along line 44 of FIGURE 1, and

FIGURE 5 is a sectional view taken substantially along line 55 of FIGURE 1.

Referring more particularly to the drawing, there is shown therein a compass comprising legs and 1.1 integrally interconnected at their upper ends by an inverted U-shaped arch 12. Integrally formed atop the arch 12 is an upstanding vertical handle 13.

The legs 10 and 11 are each provided with an inwardly directed longitudinally extending rib 14 and 15, respec- 3,208,149 Patented Sept. 28, 1965 tively, such ribs being offset with respect to each other so that, when the legs are brought together, the ribs overlap, as will be apparent from FIGURE 5.

Extending from the rib 14 and integrally formed therewith is an arcuate arm 16 provided on its side faces with indicia 17. The arm 16 protrudes through a slot 18 in the arm 11 and a tooth 19 is integrally formed on the arm 11 adjacent the slot 18 for selective engagement with serrations 20 formed in the underside of the arm 16.

A slender cylindrical member 21 having a pointed lower end 22 is formed integrally with the lower end of the leg 11 while the leg 10 is foreshortened and terminates in an integrally formed cylindrical pencil holder 23 having a longitudinal slot 24 former therein.

The device may be molded in such fashion that the legs 10 and 11 are sufiiciently far apart so that the free end of the arm 16 lies inwardly of the leg 11. The material of which the device is made is a plastic possessing memory that is to say, a material which, when forced from its normal position, will return to such normal position when tension is released.

It will be apparent that the arm 16 may be extended through the slot 18 while exerting a slight upward pressure on said arm to allow it to clear the tooth 19. When a selected position has been attained, tension may be released from the arm and it will thereupon move downwardly so that the tooth 19 may engage with one of the serrations 20. This positioning of the arm will be accomplished with exactitude for the users purposes by reading the indicia 17 with respect to the tooth 19, the indicia being formed to read, for example, the desired measurement of a radius to be inscribed by the device. It will also be apparent that the holder 23 may be of a diameter to frictionally receive a pencil of normal diameter.

While but one form of the invention has been shown and described herein, it will be readily apparent to those skilled in the art that may minor modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. A one piece compass adapted to be formed of a plastic material in a molding operation, and comprising a pair of substantially flat legs with the inner faces thereof being directed toward each other, said legs being extended to define a U-shaped arch integrally connecting the ends of said legs, there being inwardly directed longitudinally extending ribs on the opposed inner faces of said legs with said ribs being off-set with respect to each other so that said ribs will overlap when the legs are moved together, an arcuate arm having one end integrally connected to the inner face of one of said legs and the other end directed toward the other of said legs, the underside of said arcuate arm having serrations therein, there being a slot in said other leg for receiving said other end of said arcuate arm, and a tooth on said other leg adjacent said slot engageable with said arcuate arm serrations to lock said arm and said other leg in selected positions.

2. A one piece compass adapted to be formed of a plastic material in a molding operation, and comprising a pair of substantially fiat legs with the inner faces thereof being directed toward each other, said legs being extended to define a U-shaped arch integrally connecting the ends of said legs, there being inwardly directed longitudinally extending ribs on the opposed inner faces of said legs with said ribs being off-set with respect to each other so that said ribs will overlap when the legs are moved together, the outer face of each leg comprising plane surfaces sloping outwardly from the edges of said outer faces to intersect along a straight line, an arcuate arm having one end integrally connected on the inner face of one of said legs and the other end directed toward a 4 the other of said legs, the underside of said arcuate arm 499,193 6/93 Aborn 33-152 having serrations therein, there being a slot in said other 731,200 6/ 03' Miller 33152 leg for receiving said other end of said arcuate arm, and 1,958,989 5/34 Fischer 33-157 a tooth on said other leg adjacent said slot engageable with said arcuate arm serrations to lock said arm and 5 said other leg is selected positions.

References Cited by the Examiner UNITED STATES PATENTS 275,403 4/83 Neimeyer 33153 FOREIGN PATENTS 27,125 1910 Great Britain.

6,192 7/95 Sweden.

ISAAC LISANN,- Primary Examiner. 

1. A ONE PIECE COMPASS ADAPTED TO BE FORMED OF A PLASTIC MATERIAL IN A MOLDING OPERATION, AND COMPRISING A PAIR OF SUBSTANTIALLY FLAT LEGS WITH THE INNER FACES THEREOF BEING DIRECTED TOWARD EACH OTHER, SAID LEGS BEING EXTENDED TO DEFINE A U-SHAPED ARCH INTEGRALLY CONNECTING THE ENDS OF SAID LEGS, THERE BEING INWARDLY DIRECTED LONGITUDINALLY EXTENDING RIBS ON THE OPPOSED INNER FACES OF SAID LEGS WITH THE SAID RIBS BEING OFF-SET WITH RESPECT TO EACH OTHER SO THAT SAID RIBS WILL OVERLAP WHEN THE LEGS ARE MOVED TOGETHER, AN ARCUATE ARM HAVING ONE END INTEGRALLY CONNECTED TO THE INNER FACE OF ONE OF SAID LEGS AND THE OTHER END DIRECTED TOWARD THE OTHER OF SAID LEGS, THE UNDERSIDE OF SAID ARCUATE ARM HAVING SERRATIONS THEREIN, THERE BEING A SLOT IN SAID OTHER LEG FOR RECEIVING SAID OTHER END OF SAID ARCUATE ARM, AND A TOOTH ON SAID OTHER LEG ADJACENT SAID SLOT ENGAGEABLE WITH SAID ARCUATE ARM SERRATIONS TO LOCK SAID ARM AND SAID OTHER LEG IN SELECTED POSITIONS. 